Electrical switch mechanism



Nov. 17, 1942. c. E. POWELL 2,302,347

ELECTRICAL SWITCH MECHANI SM Nov. 17, 1942. c. E'. POWELL 2,302,347

ELECTRICAL SWITCH MECHANISM Original Filed June l, 1959 2 Sheets-Sheet 2in relatively limited space. I

ELECTCAL S 'i i Charles E. Powell, Wadsworth, Ohio @riginal applicationdune 1, 1939, Serial No. 276,875, now Patent No. 2,239,624, dated April22, 1941. Divided and this application March l3,\1941, Serial No.383,219

7 Claims. (Ci. 2013-67) This invention relates to electrical switchmechanism, and it has special reference to switch mechanism designedprimarily to supply the need for a contact making and breaking device'4of small current carrying capacity capable of being operated from on toofi condition and of making a great many contacts at high speed withextreme accuracy of register of its contact elements and minimum wear onits parts, and which can be made so as to have small outside dimensionsthus adapting it for'installation for use Although the switch mechanismof the invention is, as stated, adapted primarily to small switches, itwill be understood that it is not thus limited in its application.

This application is a division of my copending application of the sametitle, led June l,l 1939, Serial No. 276,875, now Patent No. 2,239,624,granted April 22, 1941.

One object of the invention is to provide a switch mechanism adapted toa variety of uses such as in combination with magnetic remote controlcounters, signals, machine tool controls, start and stop push buttons,ilqat switches, pressure switches, valve operating switches, and thelike, where a quick make and break butt c( ntact switch device capableof long life and rapid o peration with absolute dependability isrequired.

An additional object of the invention is to provide a switch mechanismwhich requires slight pressure or a short'l stroke for its operation butwhich, even so, will change from on to off position, and vice versa withgreat rapidity and com plete reliability.

Another object of the invention is to provide an electrical switchmechanism which may be of single polesingle throw, double pole, orsingle pole two-way type, or a switch mechanism which when made ofdouble pole type may readily, and without the use of tools, betransformed from a double pole single throw switch to a single polesingle throw switch or a single pole double throw switch by a simplerearrangement of parts without disturbing or changing the mounting orany mechanical connections of the switch.

A further object of the invention is to provide an electrical switchmechanism which, though essentially the same in the mechanicalarrangement of its parts, and in its mode of operation, may be made invarious types. such for example as the single pol'e rotary type, thesingle pole push button type, the double pole transformable typehereinbefore referred to, a cam operated type, and

conceivably other types, and which may be actuated by mechanical,electrical, pressure and other means to suit the requirements of variousinstallations, but which, n0 matter what its type or mode of actuation,will render eicient service when rapidly` operated, and will be capableof extensive use without attention or adjustment, repair or replacementof parts.

Without limiting the adaptability of the switch mechanism of theinvention, it may be said that in the forms shown in the drawings andhereinafter particularly described, the switch mechanism` is especiallydesigned for use in intallations operating at 10 amperes 110 volts, 5amperes 250 volts, and 1 ampere 500 volts, either alternating or directcurrent, non-inductive loads. l

A still further object of the invention is to produce a switch mechanismcapable of elcient operation wherein relatively light operating springsmay be used, thus providing for more effective operation and longer lifein that break age and distortion of the springs is not apt to occur, andalso providing for more satisfactory service in that repairs orreplacements will rarely be necessary.

Still another object of the invention is to provide contact elementshaving relatively rugged mechanical characteristics and provided, whereneeded, with insulating means able to withstand the vibration and impactof a multiplicity of contacts without mechanical or electrical failure.

A still vfurther object of the invention is to provide a switchmechanism the frame and operative parts of which are made of simpledesign and rugged wear-resisting materials, and preferably in the formof sheet metal vstampings, thus reducing production cost to the minimumwhile at the same time insuring long life and freedom from defects orfailures in service.

Another object of the invention is to provide a switch mechanism theparts of which are of relatively simple form and so constructed andassembled as to be disassembled, repaired and replaced without diicultyIand at a minimum of expense and, ordinarily, without the use of tools.

With the foregoing and other objects in view, as will appear hereinafterfrom he detailed de scription, the invention contemplates a snap switchprovided with cooperating stationary and movable contact means, andmeans for operating the movable contact means including toggle mechanismcomprising an oscillatable or shiftable member, link means providing aconnection between such member and the movable contact means, and meansfor actuating said member including resilient means providing a snapaction of said member substantially instantaneous- 1y from openswitchposition to closed switch position and vice versa, the link means beingcapable of adjustment with respect to the shiftable member to alter thecharacter and operating timing of the switch, all as particularlydescribed and claimed in my copending application hereinbefore referredto. And the invention also contemplates, and this divisional applicationis particularly directed to, various details of construction, assemblyand operation of the mechanism, particularly the construction,arrangement, mode of operation and of assembly and disassembly of theswitch contact carrying parts, all as will be explained hereinafter morefully and nally claimed.

In the accompanying drawings illustrating the invention, in the severalfigures of which like parts are similarly designated,

Figure 1 is a face view ofone type of switch embodying the features ofthe invention, the cover and certain parts being shown in section in theinterest of clearness.

Fig. 2 is a side view of the switch of Fig. 1, with the cover insection.

Fig. 3 is a section taken on the line 3-3 of Fig. 1.

Fig. 4 is a perspective view of the movable switch element assemblydetached from its pivotal mounting.

Fig. 5 is a perspective View of the stationary switch element assemblydetached from its mounting.

Fig. 6 is a sectional elevation illustrating the insulating means forthe switch element assembly.

Fig. '7 is a fragmentary face View illustrating an adjustment of themeans for operating the movable switch elements whereby the switch ofFig. 1 may be converted from one type of operation to another.

Fig. 8 is a face View of another type of switch embodying the featuresof the invention, with the cover removed.

Fig. 9 is a side view of the switch of Fig. 8 looking toward the left,with the cover shown in section.

Fig. 10 illustrates another type of switch embodying the features of theinvention.

Fig. 11 illustrates a still further type of switch embodying thefeatures of the invention.

Fig. 12 is a perspective view of a bracket assembly for mounting theparts of the movable switch element and the operating mechanismtherefore illustrated in Fig. 11, and

Fig. 13 is a perspective View of the movable switch detached from itsmounting.

Referring to Figs. 1 to 6 inclusive, it will be seen that the switchillustrated is, with its parts arranged as shown, of the single poledouble throw type, including a substantially :iL-'shaped mountingelement having a base I and back wall 2 and provided with a cover 3enclosing the operative parts of the switch, the cover 3 being removablysupported upon and secured to the mounting element by means ofappropriately arranged screws 4 engaging ears 5.

Removably attached to the back wall 2 by screws or other appropriatefastening means 6 are angle brackets 1, the oilstanding portions 8 ofwhich (see particularly Figs. 5 and 6) are substantially enclosed byapropriately bent embracing strips of insulating material 9, againstwhich bear the stationary contact and terminal carrying blocks I0, theattaching screws II of which pass through insulating sleeves I2 in theparts 8, so that the blocks I0 will be effectively insulated from themounting element and from each other. The switch contacts I3 carried bythe blocks I0 may have riveted or other appropriate connection I4therewith, and the binding screws I5 are threaded thereinto in thecustomary manner.

Attached to the base I as by screws I6 or other appropriate fasteningmeans is a suitably formed sheet metal bracket I'I designed to providebearings and the like for the movable elements of the switch mechanism,including the movable switch elements I8 and an operating disk I9.

Each of the movable switch elements I8 (see particularly Fig. 4)comprises an oscillatable arm provided with hook means 2D pivotallyengaging a pivot pin 2| carried by ears of the bracket I'I, and at itsupper end is furnished with an insulating member 22 to which is afhxedby a bolt, rivet or the like 23 a contact carrying element 24. Thiscontact carrying element 24 is insulated from the switch element I8 insubstantially the same manner as that described in connection with thestationary blocks Ill so that current will not pass from its contacts tothe brackets I1 and the switch mounting element. The contact carryingelement 24 is provided with similar L- shaped arms 25 between which isslidably positioned and guided a current carrying plate 28 backed up byan appropriately centered compression spring 21 and carrying the movableswitch contacts 28.

Adjacent to its point of pivotal connection 2| each element I8 isprovided with an offset lug 29 between which and the base of the bracketI'I is mounted a compression spring 30 tending normally to hold theswitch contacts in open -position and to maintain the pivotal connectionbetween the parts 20 and 2|. The springs 30 may be appropriatelypositioned by the heads of ihe screws or the like I6 and by centeringmeans 3i carried by the lugs 29.

The operating disk I9 is provided with a ball bearing mounting 32including a shaft 33 the ends 34 of which are slabbed off for slipengagement with bearing yokes 35 of the bracket II4 The periphery of thedisk I9 is provided with diametrically opposite pairs of bearing pointspreferably formed as recesses or sockets 38 and seating in one or theother of the recesses of each pair, as will be hereinafter more fullyexplained, are link means 31 forked at one end 38 to embrace the sidesof the disk I9 and provided with reduced lugs 39 at their other ends forengagement with appropriate slots 40 in the members I8, thus furnishingoperating connection between the disk and the members I8 to provide forshifting of the movable switch contacts 28 from closed to open positionand vice versa, the springs 38 serving to maintain operative engagementbetween the members I8, link meansV 31 and disk I9.

It will be apparent from the foregoing that oscillation of the disk I9upon its bearing 32 will function to cause operation of the switchelements from closed to open position, and vice versa,'by toggle actionof the link means 3l with respect to the members I8 and disk I9, andinasmuch as the switch mechanism is, primarily, of the quick make andbreak or snap type, means must be provided for accomplishing this toggleaction substantially instantaneously. Such mechanism is provided inaccordance with the springs 88.

By reference particularlyto Fig. 1, it will be seen that the springattaching means 41 will normally assume a position past dead center withrespect to the shaft 33 of the disk I9 and, hence, when the trip means44 are actuated the arms 45 of the yoke member 3i will be swung acrossthe axis of shaft 33 and hence their spring connecting ends 46 will putsuch tension upon the springs i8 as to cause the spring attaching means51, and with them the disk I9, to instantaneously snap over center tothe opposite past dead center position. The limits of oscillation of thevdisk I9 in response to the influence of the springs d8 are defined byan appropriate notch S9 the faces of which alternately cooperate with astop 50 carried by the bracket I1 in fixed relation to the axis ofoscillation of the disk.

It will be obvious that the counteracting forces exerted by the springs58 between their points of connection i6 and i1 with the arms B5 of theyoke 4I and disk I9 will operate to hold the shaft 35 upon which thedisk nds its bearing seated in the yoke members 35 of the bracket I1.

From the foregoing, it will be apparent that a switch of the typeillustrated in fFigs. 1, to rI inelusive may be made to operate as asingle pole double throw switch, when its parts are in the positions ofadjustment illustrated in Fig. 1, or as a double pole single throwswitch when its parts are in the position of adjustment illustrated inFig. '1, or that by completely removing one of the movable switchelements I8 and its.

actuating toggle link 31, the switch may be made to operate as a singlepole single throw switch. All of these modifications of operativecharacteristics of the switch are made possible by its structuraldetails and mode of assembly. In other words, having referenceparticularly to Figs. l and 7, if the toggle link31 at the left is movedfrom the upper recess or socket 35 of the disk I9 tothe lower recess orsocket, as shown in Fig. 7, oscillation of the disk will result insimultaneous closing and opening movement of both movable switchelements I8. Moreover, if

the link 31 at the left is maintained in the position illustrated inFig. 7, and the link 31 at the right is moved into the lower recess orsocket of the disk I3, the timing of opening and closing movement of theswitch elements I8 may be rethe respective switch Velement I8 with itscontactv elements 28 hard against the Xed contact elements I3 so thatthe spring 21 is sufficiently cornpressed to permit movement of the diskadjacent end of the toggle link 31 from one notch to the other. Suchmanipulation of the switch element I8 causes a compression of the spring21 in excess of that occurring during normal functioning of the switch,and therefore during such normal functioning there is no chance for thelink INI 31 to escape from the slot 80 of the switch element I8 and theengaged recess or socket 38 of the disk I9.

Furthermore, it is possible, without the use of tools, to disconnect themovable switch elements I8 from their pivot bearings upon the pivot pins2| merely by depressing them against the springs 30 until their hookelements 20 are released from the pivot pins 2I, and thereafter theseswitch elements and their springs 30 and toggle links 31 may be liftedout of the switch assembly.

Moreover, the disk I9 may also be disassembled without the use of tools,simply by lifting its shaft 33 out of engagement with its yoke-likesupporting members 35, tension sufficient for this purpose being putupon the springs 48.

The type of switch illustrated in Fig. 9, although embodyingsubstantially the same fixed and movable switch elements and operatingmechanism therefor as described in connection with Fig. 1, is of greateradaptability than the latter in that its mechanism may be assembledwithin a more confined space and the contour of the switch may becircular, as shown. Preferably the circular mounting element or housing5I may be provided with a plurality of equally .spaced circumferentiallyarranged openings 52 preferably tapped for cooperation with attachingscrews or the like 53 for a mounting bracket 54 having an oifstandingattaching flange 55. This mounting bracket 54 has a pair of ears 56 withwhich the screws 53 cooperate, and Vit will be apparent that thesescrews may be engaged with any two circumferentially adjacent openings52, and thus the bracket is susceptible of being mounted with respect tothe housing in any one of four positions circumferentially thereof.Moreover, the bracket may be mounted either as illustrated, with itsflange 55 extending away from the housing, or it may be reverselymounted with its flange extending toward the housing. The flexibility ofthe lmanner in which the mounting bracket 54 may be associated with thehousing 5I of the switch makes possible mounting of the switch withrespect to a supporting member in a variety of positions to adapt it tomany conceivable conditions of use.

Furthermore, if the switch cover, or the housing, is provided with arevolving cam attaching means (not shown) the switch may be coupled toany rotating element on a machine and thus be mounted to make and breakelectrical contact once during each revolution of such element, as willbe apparent from the following description of the operative parts of theswitch mechanism of these gures of the drawings (Figs. 8 and9).

As will be apparent from a further inspection of Figs 8 and 9, theoperative parts of the fixed and movable switch elements, and the toggleand snap action operating means therefor, have been given the samereference characters as those applied to similar parts appearing inFigs. 1 to '7 inclusive. However, the switch mechanism of Figs. 8 and 9is of the single pole single throw type and iS adapted normally to beheld in either open or closed circuit condition. This is accomplished byproviding theshaft 5T with which the yoke member SI oscillates with acoiled spring 58 one end of which may be engaged in a notch 59 in theend of the shaft and its other end bearing against an arm 60 attached toa yoke-shaped bracket 6I angularly adjustable upon the bearing member33, its adjustment being iixed by binding screws 62. Thus the tensionupon the spring 58 may be variedin accordance with power of the springsd8. The operatign lever 64 is adjustably mounted upon the shaft 51 bymeans of a split hub and clamping screw 65, and it may be angularlyarranged with respect to the shaft in any position necessary toaccommodate the switch to its conditions of installation with respect tothe part by which the lever 64 may be actuated.

Thus, when the toggle mechanism has been actuated by the snap actionmeans under the influence of the lever 64 to open the switch, the spring58 will return the parts to closed switch position.

The switch illustratedv ln Fig. is of the single pole single throw typeadapted for push button operation, and the parts of the mechanismthereof which correspond in nature and function to those illustrated inFigs. 1 to 7 inclusive have been given similar reference characters.

In this switch mechanism the arms 86 of a bracket 61 detachably andplvotally support the yoke member 4I', and this yoke member has anabutment member 68 providing means against which the shank 69 of a pushbutton 10 bears.

A return.spring 1I is connected between the' It will be obvious that byadjusting the toggleY link 31 of the switches of both Figs. 8 and 10from one notch 36 of the disk i9 to the other, the characteristics ofoperation of the two switches may be reversed. In other words, insteadof being normally in closed -switch position, they may be normally inopen switch position.

The switch illustrated in Fig. 11 is modified somewhat from thosehereinbefore described, and is so designed that its mechanism may beenclosed within a smaller casing or housing than the others. Moreover,its construction is somewhat simplied and cheapened but withoutsacricing any of the eiilcient operative characteristics of the otherswitches. In this type of switch a cam 13 mounted upon a shaft 1li towhich an actuating member (not shown) is attached, bears against a step15 provided on one of the arms 45' of the yoke member of the snap actionmechanism. The opposite face of this step 15 bears against a returnspring 16. The disk I9' may have a plain bearing, instead of a ballbearing, in hook-shaped arms 11 of a bracket 18 (Fig. 12) and thisbracket 18 also furnishes bearings 19 for the arms d5' of the yokemember, and bearings 80 for the pivot pin of the movable switch elementI8'. This movable switch element I8' (Fig. 13) instead of being providedwith the mounting means 24, 25, 26, 21 of Figs. 1 to 10 inclusive, hasits contact elements 8l mounted upon a current carrying bar 82 axed to aspring arm 83 between which and the bar 82 suitable insulation 8B isinterposed.

The switch of Fig. l1 is of the single pole single throw type and withits parts in the adjustment illustrated, is normally in closed switchcondition. However, as in the case of the switches of Figs. 8 and 10,this switch also may be adjusted to be normally in open switchcondition.

All of the insulated parts of the switch mechanism may, after assembly,be appropriately coated with a suitable lacquer and baked, if desired,thus providing not only for more effective insulation but tending togreater security of assembly.

It will be apparent that the switch mechanism of the invention is of thequick make and break butt contact type, and that it will be positivelyon or on for any-appropriate motion past dead center of the operatingyoke member of the snap action mechanism. Moreover, due to the resilientmounting of the movable contact elements 28 and 8| there will beadequate similar contact pressure between the fixed and movable contactelements regardless of the amount of motion imparted to the operatinglever to actuate the snap action mechanism. This does away with thepossibility of having a tittering or weak contact with the accompanyingheating and burning of the contact elements even at light loads or underconditions of operation where the motion of the machine to which theswitch is attached is very slow, or Where such motion is stopped just atthe point of actuation of the switch mechanism.

It will be noted, furthermore, that the' switch mechanism of theinvention embodies in its operative characteristics the feature ofpositively maintaining or locking the contacts in the on orcontact-making position in such manner that no amount of pressure actingdirectly against the contact bar can force it back, nor will any amountof vibration loosen the contact.

VAlthough the switch mechanism of the invention has been particularlydisclosed as including an oscillatable disk I9 as the shiftable memberof the snap action toggle mechanism, it is con -v movable switch,element carrying one of said contact members, separable pivot means forsaid element, and resilient means serving normally to separate saidcontact members by rotative movement of said element about said pivotmeans and to hold the element in open switch position, said resilientmeans serving also to maintain said pivot means intact.

2. In electrical switch mechanism including a pair of relatively movablecontact members, a movable switch element carrying one of said contactmembers, separable lpivot means for said element including a fixed pivotpin and hook means on said element, and resilient means serving normallyto separate said contact members by rotative movement of said elementabout said pivot means and to hold the element in open switch position,said resilient means serving also *'1 to maintain said hook means inengagement with said pivot pin.

switch element, and resilient means having a fixed bearing and a bearingupon said switch element and serving normally to separate said contactmembers by rotative movement of said element about said xed pivot and tohold the switch element in open switch position, said resilient meansserving also to maintain said separable pivot means in operativeengagement by pressure exerted longitudinally of the switch element.

4. In electrical switch mechanism including a pair of relatively movablecontact members, a movable switch element, separable pivot means forsaid switch element including a xed pivot member and hook means carriedat one end of said switch element and normally in releasable engagementwith said pivot member, one of said contact members being carriedadjacent to the opposite end of said switch element, and resilient meanshaving a fixed bearing and a bearing upon said switch element andserving normally to separate said contact members by rotative movementof said element about said iixed pivot and to hold the switch element inopen switch polsition, said resilient means serving also to maintainsaid separable pivot means in operative engagement by pressure exertedlongitudinally of said switch element.

5. In electrical switch mechanism including relatively iixed and movableparts, a movable switch element, separable pivot means for said switchelement, a shiftable member for actuating said switch element, linkmeans interposed between and loosely bearing upon said switch elementand said shiftable member, and resilient means interposed between saidswitch element and a fixed part and serving normally to hold the switchelement in open position and to maintain said pivot means intact, andserving also to maintain the bearing relation of said link means betweensaid switch element and said shiftable member intact. I

6. In electrical switch mechanism, a movable switch element, separablepivot means for said switch element, an oscillatable member foractuating said switch element, separable bearing means for saidoscillatable member, link means interposed between and loosely bearingupon said switch element and oscillatable member, resilient meansserving normally to hold the switch element in open position and tomaintain said pivot means intact, and serving also to maintain thebearing relation of said link means between said switch element and saidoscillatable member intact, and other resilient means serving normallyto hold said oscillatable member in its bearing means and to impart toit switch-operating snap action.

7. In electrical switch mechanism, a movable switch element, separablepivot means for said switch element, an oscillatable member foractuating said switch element, separable bearing means for saidoscillatable member, link means interposed between and loosely bearingupon said switch element and oscillatable member, compression springmeans serving normally to hold the switch element in open position andto maintain said pivot means intact, and serving also to maintain thebearing relation of said link means between said switch element and saidoscillatable member intact, and tension spring means serving normally tohold said oscillatable member in its bearing means and to impart to itswitch-operating snap action, said switch element, link means andoscillatable member being removable from the switch mechanism Withoutthe use of tools upon appropriate compression of said compression springmeans and extension of said tension spring means.

CHARLES E. POWELL.

